Method and device for regulating cylindrical optical path

In the invention, the path of an incident ray is changed into a screw type by a cylindrical reflection tube so as to achieve the aim of increasing the optical path and ensure little outside interference as the optical path is reflected completely in a closed space, thereby ensuring strong capacity of resisting disturbance. The invention firstly provides a cylindrical optical path regulating devicecomprising a rotary-type reflection component, a power gear and a fixation device, wherein the rotary-type reflection component is provided with an optical reflection cylindrical component, and a tube is internally provided with an optical reflection layer fixed on a rotating platform which uses a rotating pivot as the axis and can rotate at a degree ranging from 0 to 90 degrees; the power gear is connected with a stepper motor to accurately control the rotating angle of the rotating platform; and the fixation device comprises an incidence optical generator fixed platform in a sector surfaceof 90 degrees, wherein the